mRNA alternative polyadenylation in B cell development

B 细胞发育中的 mRNA 替代多腺苷酸化

• 批准号: 10880882
• 负责人: Roger Sciammas
• 金额: $ 6.62万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-26 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10880882
• 关键词: Alleles; Alternative Splicing; Antibodies; Antibody Response; Autoimmune Diseases; B-Cell Activation; B-Cell Development; B-Lymphocytes; Binding; Biochemical; Biological Process; CRISPR screen; Cell physiology; Cells; Complex; Data; Development; Disease; Gene Expression Regulation; Genes; Immune response; Immunoglobulin M; Individual; Link; Malignant Neoplasms; Membrane; Messenger RNA; Modeling; Neurodegenerative Disorders; Pattern; Play; Poly A; Polyadenylation; Post-Transcriptional Regulation; Process; Protein Isoforms; Proteins; RNA Processing; RNA-Binding Proteins; Regulation; Reporter; Reporting; Role; Signaling Protein; Testing; Transcript; Transcriptional Activation; Transcriptional Regulation; Work; cell mediated immune response; design; gene network; genetic approach; genome-wide; insight; novel; transcription factor; vaccine development

Project summary: The vast majority of mammalian genes produce alternatively processed mRNAs through alternative splicing and alternative polyadenylation (APA). Different mRNA isoforms produced from the same gene can encode distinct proteins and/or they may be differentially regulated. Recent studies have revealed essential roles of mRNA alternative processing in many biological processes and mis-regulation of alternative splicing and APA has been causally linked to a wide range of diseases, including cancer and neurodegenerative diseases. However, the mechanism and functions of alternative mRNA processing remain poorly understood.Antibody secretion by B cells is a major component of our immune response and mis-regulated antibody response underlies many auto-immune diseases. B cell activation and differentiation require a sophisticated gene regulation cascade. Previous works, including ours, have provided insights into the transcriptional regulation mechanisms governing this process. However, it is clear that post- transcriptional gene regulation, such as alternative splicing and APA, also play an important role. In 1980, several landmark studies reported the first example of alternative RNA processing: the Immunoglobulin M (IgM) heavy chain gene (IghM) produces two APA isoforms, which encode a membrane-bound and a secreted IgM respectively. Additionally the IghM APA is developmentally regulated. Subsequent studies, however, have failed to provide a consistent mechanistic model for this APA switch. Furthermore, it remains unknown how widespread the APA regulation network is and what the functional impact of APA regulation is during B cell activation and differentiation. In our preliminary studies, we provided evidence that transcription factors, core mRNA 3’ processing factors, and RNA-binding proteins regulate IghM APA. In addition, we discovered that B cell activation leads to a significantly change in the APA patterns of ~900 genes, including those encoding key cell fate regulators and signaling proteins. Based on these preliminary results, we hypothesize that the APA of IghM and a large gene network are regulated at multiple levels and that APA regulation plays an important role in B cell functions. To test these hypotheses, we have designed the following specific aims: 1) Identify regulators of B cell activation-induced IghM APA switch using a biochemical and genetic approach; 2) Systematically characterize the mechanisms of B cell activation-induced IghM APA switch; 3) Determine the role of APA regulation in B cell activation and differentiation. Successful completion of the proposed studies will provide fundamental insights into APA regulation and function. More importantly, our results will reveal the role of post-transcriptional gene regulation in B cell development and B cell- mediated immune response, which will pave the way for better strategies for developing vaccines and treatment for autoimmune diseases.

项目概要： 绝大多数哺乳动物基因通过替代加工产生 mRNA 选择性剪接和选择性多聚腺苷酸化（APA）。产生不同的 mRNA 亚型 来自同一基因的不同蛋白质可以编码不同的蛋白质和/或它们可能受到差异性调节。 最近的研究揭示了 mRNA 选择性加工在许多生物中的重要作用 选择性剪接和 APA 的过程和错误调节与广泛的 一系列疾病，包括癌症和神经退行性疾病。然而，该机制 替代 mRNA 加工的功能仍然知之甚少。 B 分泌抗体 细胞是我们免疫反应和错误调节的抗体反应的主要组成部分 是许多自身免疫性疾病的基础。 B 细胞的激活和分化需要复杂的 基因调控级联。以前的工作，包括我们的工作，提供了对 控制这一过程的转录调控机制。然而，很明显的是，后 转录基因调控，例如选择性剪接和 APA，也发挥着重要作用。 1980 年，几项具有里程碑意义的研究报道了替代 RNA 加工的第一个例子： 免疫球蛋白 M (IgM) 重链基因 (IghM) 产生两种 APA 亚型，编码 分别为膜结合型和分泌型 IgM。此外，IghM APA 正在发展中 受监管。然而，随后的研究未能提供一致的机制模型 对于此 APA 开关。此外，目前尚不清楚 APA 监管的范围有多大。 B 细胞激活过程中 APA 调节的功能影响是什么？ 差异化。在我们的初步研究中，我们提供的证据表明转录因子、核心 mRNA 3' 加工因子和 RNA 结合蛋白调节 IghM APA。此外，我们 发现 B 细胞激活导致约 900 个基因的 APA 模式发生显着变化， 包括那些编码关键细胞命运调节剂和信号蛋白的蛋白。基于这些 初步结果，我们假设 IghM 的 APA 和一个大的基因网络受到调节 在多个层面上，APA 调节在 B 细胞功能中发挥着重要作用。为了测试这些 假设，我们设计了以下具体目标：1）识别B细胞的调节因子 使用生化和遗传方法激活诱导 IghM APA 开关； 2）系统地 描述 B 细胞激活诱导 IghM APA 转换的机制； 3）确定角色 B 细胞活化和分化中 APA 调节的研究。顺利完成拟议的 研究将为 APA 调节和功能提供基本见解。更重要的是，我们的 结果将揭示转录后基因调控在 B 细胞发育和 B 细胞中的作用 介导的免疫反应，这将为开发疫苗的更好策略铺平道路 和自身免疫性疾病的治疗。